Stabilise before you sweeten

A dry mead has no sugar left for its yeast. Sweeten it with honey and the yeast has a meal; in a corked bottle its gas has nowhere to go, and the bottle can burst: a bottle bomb.

So meadmakers stabilise first, with two things. Potassium sorbate, about 1 gram a gallon, gives the usual 200 milligrams of sorbic acid a litre and stops yeast multiplying; US wine law allows 300. Potassium metabisulphite, about a third of a gram a gallon, adds about 50 parts per million of sulphur dioxide against bacteria and air. Sorbate cannot stop a running ferment, so this waits for three steady readings; without sulphite, bacteria can turn sorbate to a geranium smell.

In this game Stabilise runs whenever a bottle would hold sugar: any batch finishing at 1.010 or above, sweetened, stuck or left sweet by its yeast. So the cellar makes no bottle bombs.